Parity theories are used to study the "rand" / "dollar" rate. Interest rate parity results suggest that in about 20% to 26.7% of cases, investing in USA would have yielded higher interest returns than investing in South Africa. In 73.3% to 80% of cases, investing in South Africa would have yielded more interest returns. The PPP theory suggests rand undervaluation relative to the dollar, thereby justifying revaluation / appreciation in all cases, while the interest rate parity theory suggests rand undervaluation in 73.3% to 80% of cases and overvaluation in 20% to 26.7% of cases. Cointegration tests suggest significant (at 5% but not at 1%) long run PPP, which is consistent with the high correlation (0.97) between the two countries’ price levels.